1. Field of the Invention
This invention is directed to a latching relay switch assembly, in general, and to such a latching switch assembly in which the coil section is hermetically separated from the switch section, in particular.
2. Prior Art
There are many types of switches and relays which are known in the art. These switches and relays are often arranged together to form a solenoid or the like. The electrical relay is, generally, a device which utilizes the variation of current in one electric circuit as a controlling factor in another. For example, a change in current in one circuit may cause or permit a current in another circuit, in response to the operation of an intermediate relay. The relays, switches and/or solenoids which are known in the art are almost too numerous to enumerate herein. These relays have been widely used, particularly in automatic or semi-automatic devices, for the protection or operation of electric power equipment, or for communication systems. Suitable relays may detect over-current, under-current, over-voltage, under-voltage, overload, reverse current, reverse power, abnormal frequency, high temperature, short circuits, phase unbalance, or the like. Relays may be highly specialized protective relays which will detect an abnormality and, for example, open (or close) a circuit associated with the abnormality. Commonly, relays are used as a means to direct current from an electrical supply to a load circuit.
However, the known and existing relay switches have certain shortcomings when constructed as a single chambered, unitary device. In many applications, this is a problem because of the potential for interaction between the control circuits (i.e. coils) and the switching circuits and armature. Also, it is possible that the switching portion of the device can be contaminated by the components and materials which are utilized in the coil section. Thus, even in hermetically sealed devices, failures due to corrosion or the like can occur. The outgas or vapor products associated with the commonly used organic materials required for coil construction have historically caused organic films to occur on the contact surfaces of the switches which cause high contact resistance and in some cases, even cause open circuits. Likewise, particulate shedding from the coil assembly can also be a problem. Also the known and existing relays of subminiature configuration commonly stick in a null position because of friction in the armature suspension system.